1. Field of the Invention
The present invention relates to a piezoelectric actuator that is fabricated by using so-called aerosol deposition (AD) that performs film deposition by mixing a raw material with a gas and ejecting the mixture from a nozzle so that the same collides with a substrate, and to an inkjet head and fabrication methods thereof.
2. Description of the Related Art
As an example of a piezoelectric actuator that is used in an inkjet head or the like, there is a piezoelectric actuator that comprises an ink flow path formation member in which a plurality of pressure chambers is formed, wherein a substrate that constitutes a portion of the wall surface of each of the pressure chambers is bent by means of a piezoelectric material layer that is provided on the substrate so that ink in the pressure chambers is ejected out from a nozzle that communicates with the pressure chamber (See Japanese Patent Application Laid Open No. H11-70653), for example). In such a piezoelectric actuator, in cases where the piezoelectric material layer is provided over the whole area of the substrate surface, the piezoelectric material layer is bent locally by individually arranging one electrode (individual electrode) in a position that corresponds with each pressure chamber on the surface of the piezoelectric material layer and applying an electric field between the electrode and a conductive substrate that is used as a common electrode. However, in this case, vibrations are transmitted to the periphery of the bent part of the piezoelectric material layer and, as a result, there is a variation in the ejection speed and volume, and so forth when the ink is ejected from an adjacent pressure chamber. Based on a situation where such so-called crosstalk and so forth is to be prevented, the piezoelectric material layer is not provided over the whole area of the substrate surface and it is desirable to provide the piezoelectric material layer only in a partial region that corresponds to the pressure chamber.
As means for forming the piezoelectric material layer only in a partial region, a method that forms a resist with a predetermined pattern on the substrate surface, forms a piezoelectric material layer by means of aerosol deposition (AD) over the whole area of the upper surface, removes the resist and then leaves behind a piezoelectric material layer on the substrate in the form of a pattern may be considered, for example. However, with this method, there has been the problem that, when the resist is removed, the piezoelectric material layer is split and there is the risk that chips, cracks, and so forth will be produced in the piezoelectric material layer on the substrate.